<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>alert| confirm| prompt</title>
</head>
<body>
	<script type="text/javascript">
		window.alert('mjj');
		var a = window.confirm('你确定要离开网站?');
		console.log(a);
		var name = window.prompt('请输入你早晨吃了什么?','mjj');
		console.log(name);
	</script>
</body>
</html>